Zuckerberg said he wanted the site's users - rather than Facebook executives or outside experts - to determine how news outlets rank in terms of trustworthiness.

"There's too much sensationalism, misinformation and polarisation in the world today," he wrote in a Facebook post.

"Social media enables people to spread information faster than ever before, and if we don't specifically tackle these problems, then we end up amplifying them.

"That's why it's important that News Feed promotes high quality news that helps build a sense of common ground."

The change - which is being tested first in the US from next week - will affect posts by media outlets and news stories that individuals share, Facebook said.

Image:Facebook will ask users if they trust news sources

The quality of news on Facebook has been called into question since the 2016 US election campaign when users saw hoaxes saying Pope Francis endorsed Donald Trump and a federal agent investigating Hillary Clinton had been found dead.